• Title/Summary/Keyword: Simulation of fire

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Smart Vision Sensor for Satellite Video Surveillance Sensor Network (위성 영상감시 센서망을 위한 스마트 비젼 센서)

  • Kim, Won-Ho;Im, Jae-Yoo
    • Journal of Satellite, Information and Communications
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    • v.10 no.2
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    • pp.70-74
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    • 2015
  • In this paper, satellite communication based video surveillance system that consisted of ultra-small aperture terminals with small-size smart vision sensor is proposed. The events such as forest fire, smoke, intruder movement are detected automatically in field and false alarms are minimized by using intelligent and high-reliable video analysis algorithms. The smart vision sensor is necessary to achieve high-confidence, high hardware endurance, seamless communication and easy maintenance requirements. To satisfy these requirements, real-time digital signal processor, camera module and satellite transceiver are integrated as a smart vision sensor-based ultra-small aperture terminal. Also, high-performance video analysis and image coding algorithms are embedded. The video analysis functions and performances were verified and confirmed practicality through computer simulation and vision sensor prototype test.

Analysis of the impact of the land surface resolution on soil moisture and fire simulation (지면 모델 격자 크기에 따른 토양수분과 화재 모의 영향 분석)

  • Hocheol Seo;Eunjee Lee;Randal D. Koster;Yeonjoo Kim
    • Proceedings of the Korea Water Resources Association Conference
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    • 2023.05a
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    • pp.69-69
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    • 2023
  • 격자 기반의 지면모형을 구동하기에 앞서 사용자의 목적에 따른 모델의 정확도와 모델의 구동 시간의 적절한 균형을 이루는 지면 모델의 격자 크기의 설정은 중요하다. 특히, 격자 크기에 따라 화재 모의 결과 영향이 매우 클 수 있지만, 이에 관한 연구들을 거의 이루어지지 않았다. 화재 모의는 탄소 순환뿐만 아니라 물 순환에도 직접적인 영향을 미치기 때문에 이를 위한 적절한 격자 크기 설정은 중요하다. 본 연구에서는 지면모형인 NCAR Community Land Model version 5(CLM 5)-biogeochemistry (BGC) 모형과 2000년부터 2019년의 The Modern-Era Retrospective analysis for Research and Applications, Version 2 (MERRA-2) 기상자료 이용하여서 지면 모델 격자 크기(1.9°×2.5°, 0.47°×0.63°, 0.25°×0.25°)에 따른 전 지구 규모의 화재 시뮬레이션 결과들을 분석하였다. 연평균 화재면적은 격자 크기가 제일 큰 1.9°×2.5° 격자의 시뮬레이션에서 연평균 450M ha로 가장 작게 나타났으며 격자의 크기가 작아질수록 화재의 크기는 증가하는 것으로 나타났다. 지면 모델의 격자가 작아짐에 따라 토양 입자의 분포가 세분화되고 이에 따라 투수 계수값이 증가하며 높은 토양수분의 분포들을 줄어들고 낮은 토양수분의 분포는 증가함을 확인하였다. 토양수분이 줄어듦에 따라 화재 연소성 정도를 나타내는 변수의 값이 증가하고 이에 따라 화재 발생빈도 및 화재 확산이 증가하여 지면 모델의 화재면적을 더 증가시키는 요인이 됨을 확인하였다. 이 연구를 바탕으로 하여 화재 모의의 불확실성 요소를 이해하고, 격자 크기에 따라 화재 모의 관련 매개변수의 수정이 필요할 것으로 판단된다.

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The effects of out of hospital ACLS simulation training on the paramedic's duty ability (구급대원의 전문심장소생술 시뮬레이션훈련이 직무수행융합능력에 미치는 영향)

  • Park, Yoo-Na;Cho, Byung-Jun;Kim, Gyoung-Young
    • Journal of the Korea Convergence Society
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    • v.10 no.4
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    • pp.99-106
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    • 2019
  • The purpose of this study is to analyze the effects of the simulation-based professional cardiac resuscitation training on the performance of professional cardiac resuscitation performed by paramedics in the pre-hospital stage and to provide basic data for effective cardiac resuscitation. This study is an experimental study of the design before and after the control of non-equality. The subjects of this study were 16 newly recruited paramedics from K firefighting school. The simulation training program and evaluation papers used as the evaluation tool were reviewed and commented by 6 ACLS simulation experts (2 emergency medical doctor, 2 emergency medical professors, 2 KALS instructors)Respectively. The training consisted of 30 minutes of theory and 150 minutes of practical training. The lecturer first demonstrated for 5 minutes, and after training by individual debriefing after individual training, individual and team education was conducted The evaluation scale was given a 5 - point Likert scale. The SPSS 22.0 program for Windows was used. The general characteristics of the subjects were analyzed for frequency, the examination of homogeneity between the experimental group and the control group wasfulfilled by t test, and the difference test between the groups of the two groups was performed using the paired t-test. The homogeneity test was able to confirm the homogeneity between experimental group and control group. In the evaluation of six ACLS techniques, it was proven that the experimental group that received the simulation training had better performance in all aspects than the non - training control group. The following are the technical items to be performed. 1. Electrocardiogram 2. Specialized instrument 3. Treatment of fluid 4. Leadership and teamwork 5. Medical guidance 6. Evaluation during transfer. It was proved that paramedics who received simulation training were improved on their job performance ability than general lecture and training group. Therefore, if simulation training and education are applied to a student in the synthetic course or an emergency resident who is engaged in clinical practice, he / she will be able to perform his / her duties more proficiently. It is expected that emergency services provided to patients with cardiac arrest will be improved.

Numerical Simulation of Full-Scale Crash Impact Test for Fuel Cell of Rotorcraft (회전익항공기 연료셀 충돌충격시험 Full-Scale 수치모사)

  • Kim, Hyun-Gi;Kim, Sung Chan;Kim, Sung Jun;Kim, Soo Yeon
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.26 no.5
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    • pp.343-349
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    • 2013
  • Crashworthy fuel cells have a great influence on improving the survivability of crews. Since 1960's, the US army has developed a detailed military specification, MIL-DTL-27422, defining the performance requirements for rotorcraft fuel cells. In the qualification tests required by MIL-DTL-27422, the crash impact test should be conducted to verify the crashworthiness of fuel cell. Success of the crash impact test means the improvement of survivability of crews by preventing post-crash fire. But, there is a big risk of failure due to huge external load in the crash impact test. Because the crash impact test itself takes a long-term preparation efforts together with costly fuel cell specimens, the failure of crash impact test can result in serious delay of a entire rotorcraft development. Thus, the numerical simulations of the crash impact test has been required at the early design stage to minimize the possibility of trial-and-error with full-scale fuel cells. Present study performs the numerical simulation using SPH(smoothed particle hydro-dynamic) method supported by a crash simulation software, LS-DYNA. Test condition of MIL-DTL-27422 is reflected on analysis and material data is acquired by specimen test of fuel cell material. As a result, the resulting equivalent stresses of fuel cell itself are calculated and vulnerable areas are also evaluated.

Numerical Simulation of Crash Impact Test for Fuel Tank of Rotorcraft (회전익항공기용 연료탱크 충돌충격시험 수치모사 연구)

  • Kim, Hyun-Gi;Kim, Sung-Chan;Lee, Jong-Won;Hwang, In-Hee;Kim, Kyung-Soo
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.24 no.5
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    • pp.521-530
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    • 2011
  • Since aircraft fuel tanks have many interfaces connected to the airframe as well as the fuel system, they have been considered as one of the system-dependent critical components. Crashworthy fuel tanks have been widely implemented to rotorcraft and rendered a great contribution for improving the survivability of crews and passengers. Since the embryonic stage of military rotorcraft history began, the US army has developed and practised a detailed military specification documenting the unique crashworthiness requirements for rotorcraft fuel tanks to prevent most, hopefully all, fatality due to post-crash fire. The mandatory crash impact test required by the relevant specification, MIL-DTL-27422D, has been recognized as a non-trivial mission and caused inevitable delay of a number of noticeable rotorcraft development programs such as that of V-22. The crash impact test itself takes a long-term preparation efforts together with costly fuel tank specimens. Thus a series of numerical simulations of the crash impact test with digital mock-ups is necessary even at the early design stage to minimize the possibility of trial-and-error with full-scale fuel tanks. In the present study the crash impact simulation of a few fuel tank configurations is conducted with the commercial package, Autodyn, and the resulting equivalent stresses and internal pressures are evaluated in detail to suggest a design improvement for the fuel tank configuration.

Integrated Scenario Authoring Method using Mission Impact Analysis Tool due to Cyber Attacks (사이버공격에 의한 임무영향 분석 도구를 이용한 통합시나리오 저작 방법)

  • Yonghyun Kim;Donghwa Kim;Donghwan Lee;Juyoub Kim;Myung Kil Ahn
    • Journal of Internet Computing and Services
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    • v.24 no.6
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    • pp.107-117
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    • 2023
  • It must be possible to assess how combat actions taking place in cyberspace affect the military's major mission systems and weapon systems. In order to analyze the mission impact caused by a cyber attack through cyber M&S, the target mission system and cyber warfare elements must be built as a model and a scenario for simulation must be authored. Many studies related to mission impact analysis due to cyber warfare have been conducted focusing on the United States, and existing studies have authored separate scenarios for physical battlefields and cyber battlefields. It is necessary to build a simulation environment that combines a physical battlefield model and a cyber battlefield model, and be able to integrate and author mission scenarios and cyber attack/defense scenarios. In addition, the physical battlefield and cyber battlefield are different work areas, so authoring two types of scenarios for simulation is very complicated and time-consuming. In this paper, we propose a method of using mission system information to prepare the data needed for scenario authoring in advance and using the pre-worked data to author an integrated scenario. The proposed method is being developed by reflecting it in the design of the scenario authoring tool, and an integrated scenario authoring in the field of counter-fire warfare is being performed to prove the proposed method. In the future, by using a scenario authoring tool that reflects the proposed method, it will be possible to easily author an integrated scenario for mission impact analysis in a short period of time.

Study on the Establishment of a Safety Allowance Level of Disastrous and Hazardous Facilities in Large Cities (대도시 위해.위험시설에 대한 안전도 수용기준 정립에 관한 연구)

  • 고재선;윤명오
    • Fire Science and Engineering
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    • v.15 no.1
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    • pp.84-92
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    • 2001
  • In today's world, rise in the establishment of social infrastructure resulting from population saturation in large cities has led to more extensive and frequent use of chemical materials on facilities. A result, unexpected and serious accidents, hazards, contingencies and disasters are more prevalent than ever. Such phenomenon calls for more devoted and concerted efforts towards finding ways to reduce the safety hazards that are seen to take place more often than before with the increase in the number of facilities that are prone to bring disaster and hazard coupled with the conventional safety problems that continue to exist even today. In developed countries, such challenge is addressed by various appropriate countermeasures drawn up by local professional committees on industrial facilities, whose members conduct offsite and onsite evaluation un the potential industrial disasters and its seriousness and provide their advice thereof. Against this backdrop, this study aims at identifying a comprehensive safety allowance level (safety acceptable level) when imposing limitation on the development of conventional or new facilities, for the fur pose of establishing a safety allowance level of disastrous and dangerous facilities in Korea. This is done by assessing and applying the level of danger each individual is exposed to in a randomly selected region (disastrous and dangerous areas in Seoul) based on probability of quantitative hazards, as well as simulation and calculation methods which include: i) social disaster evaluation method applying Quantified Risk Assessment of Health & Safety Executive of UK and Matrix of Risk of Evaluated Sources of Hazard; ii) Fault Tree or Event Tree Analysis and etc.

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A Study on Characteristics and Modeling of CMV by Grounding Methods of Transformer for ESS (ESS용 변압기의 접지방식에 의한 CMV 모델링 및 특성에 관한 연구)

  • Choi, Sung-Moon;Kim, Seung-Ho;Kim, Mi-Young;Rho, Dae-Seok
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.22 no.4
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    • pp.587-593
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    • 2021
  • Since 2017, a total of 29 fire accidents have occurred in energy storage systems (ESSs) as of June 2020. The common mode voltage (CMV) is one of the electrical hazards that is assumed to be a cause of those fire accidents. Several cases of CMV that violate the allowable insulation level of a battery section are being reported in actual ESS operation sites with △-Y winding connections. Thus, this paper evaluates the characteristics of CMV. An ESS site was modeled with an AC grid, PCS, and battery sections using PSCAD/EMTDC software. As a result of a simulation based on the proposed model, it was confirmed that characteristics of CMV vary significantly and are similar to actual measurements, depending on the grounding method of the internal transformer for PCS. The insulation level of the battery section may be severely degraded as the value of CMV exceeds the rated voltage in case of a grounding connection. It was found that the value of CMV dramatically declines when the internal transformer for PCS is operated as non-grounding connection, so it meets the standard insulation level.

Variation Range for Maintenance Costs of Education Facilities Based on LCC Analysis (LCC기법을 통한 교육시설물의 유지관리비 변동범위 분석)

  • Kim, Yong-Su;Kang, Hyun-Wook
    • Korean Journal of Construction Engineering and Management
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    • v.11 no.3
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    • pp.72-79
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    • 2010
  • The purpose of this study is to analysis variation of range estimation for maintenance costs of education facilities based on LCC. The adapted research method selected three education facilities in Gyeonggi-Do region. On the basis of actual maintenance costs and analyzed estimation maintenance costs are compared for analyzing standard deviation and coefficient of variation. The research of this study are as follows: 1) The average actual maintenance costs for 1,317million won and each part of average ratio exterior 19%, interior 28%, electricity & fire fighting 22%, water supply & healthy 18%, heating & water supply 13%. 2)The average analysis maintenance costs for 1,920million won and each part of average ratio exterior 20%, interior 25%, electricity & fire fighting 22%, water supply & healthy 20%, heating &water supply 13%.. 3) The analysis variation of ranges for average costs 1,619million won for minimum costs 1,409million, maximum costs 1,813million won.

The Effect of Two Fingers-Chest Compression Using the Supporting Instrument During Infant Cardiopulmonary Resuscitation (영아 심폐소생술시 지지대를 사용한 두 손가락 가슴 압박의 효과)

  • Jung, Gook-Young;Roh, Sang-Gyun;Shin, So-Yeon;Yun, Jong-Geun
    • Fire Science and Engineering
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    • v.29 no.1
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    • pp.67-72
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    • 2015
  • This paper aims to compare the effectiveness of the chest compression when a person pushes on the infant's chest by using two fingers with the support during infant cardiopulmonary resuscitation, with the effectiveness of it without the support, and to find which one is better. For the study, 50 college woman students were tested during the simulation and the result of the test has been analyzed by chi-square test, Fisher's exact test. In case of the chest compression by using the support, the depth of the chest compression comes to $3.73{\pm}0.33cm$. On the other hand, in case of the chest compression without the support, $2.50{\pm}0.59cm$. It is founded that the method of pushing on the chest by using the support is more effective than that without the support (p < 0.001). It is concluded that the way that a person pushes on the infant's chest by using two fingers with the support during infant cardiopulmonary resuscitation has turned out to be more effective and useful. It is thought that in the future, the further study for it should be conducted.